In a radio frequency (“RF”) system, when a subscriber 100 enters a site, it sends affiliation data to a central processor 102 via a control channel as illustrated in FIG. 1. Once affiliated, the subscriber 100 may submit a data request 200 on the control channel 202 as illustrated in FIG. 2. If the central processor 102 finds that there is sufficient bandwidth available on the data channel at the site, the central processor 102 sends a grant 204 to the subscriber 100. The subscriber 100 then goes to the channel 206 indicated within the grant 204. Data service for the subscriber 100 begins on the data channel 206, and the subscriber 100 stays on the data channel 206 until data service has ended 208 (i.e., all data has been transmitted and/or received).
If, however, there is not sufficient bandwidth available on the data channel 206, the central processor 102 sends the subscriber 100 a busy signal 300 and places the subscriber 100 in a queue (not shown) as illustrated in FIG. 3. When bandwidth becomes available on the data channel 206, the central processor 102 sends the subscriber 100 a grant for data service 302; as in FIG. 2, once data service for the subscriber 100 begins on the data channel 206, the subscriber 100 stays on the data channel 206 until data service has ended 208. The busy signal scenario illustrated in FIG. 3 occurs in today's systems when a maximum number of subscribers have been assigned to all data channels. As such, collisions on the data channel may cause data service time for a subscriber to be long and the bandwidth per subscriber to be low as illustrated in FIG. 4; in other words, deterioration of useful bandwidth on RF data channels exists due to collisions between transmitting subscribers, and too many subscribers attempting to send data on a data channel increases the amount of time necessary for a subscriber to acquire bandwidth for its transmissions.
Thus, there exists a need for a subscriber to request reassignment to a new data channel when the subscriber is unable to acquire sufficient bandwidth on the data channel due to collisions with other transmitting subscribers on the same data channel.